Sheet manufacturing apparatus

ABSTRACT

A sheet manufacturing apparatus includes a crusher unit, a defibrator unit, a second web forming unit, and a shaping unit. The crusher unit coarsely crushes a raw material that contains fibers into coarsely crushed pieces. The defibrator unit defibrates coarsely crushed pieces into defibrated material. The second web forming unit forms a web by accumulating defibrated material. The shaping unit forms a sheet from the web. The crusher unit is positioned vertically below the shaping unit.

BACKGROUND

1. Technical Field

The present invention relates to a sheet manufacturing apparatus.

2. Related Art

Technologies for manufacturing paper in a dry method by using wastepaper as a raw material have been disclosed (see JP-A-50-69306). A wastepaper recycling apparatus shown in FIG. 1 in JP-A-50-69306 has aone-line configuration in which a turbo cutter (coarse fiber crusher), aturbo mill that performs disintegration, preparation, and mixture in adry process, a cyclone that removes undesired matters, a screen thatremoves undefibrated fiber and the like, a sheet forming apparatus thatforms a sheet, a pick-up apparatus, a smooth presser, a dryer unit, anda pope reel are arranged in a line.

However, the waste paper recycling apparatus described in JP-A-50-69306,due to having a one-line configuration in which all the process unitsare arranged in a line, is horizontally long, so that, while being ableto be installed in factories and the like without a problem, the wastepaper recycling apparatus suffers from a problem of being large in sizewhen the apparatus is to be installed in an office, a relatively smallvacant shape in a warehouse, etc.

SUMMARY

An advantage of some aspects of the invention is that a sheetmanufacturing apparatus whose foot print (installation area) is smalland therefore improves ease of installation is provided.

This advantage can be at least partially achieved by the followingaspect and embodiments of the invention.

A sheet manufacturing apparatus according to an aspect of the inventionincludes a crusher unit configured to coarsely crush raw material thatcontains fiber into coarsely crushed pieces, a defibrator unitconfigured to defibrate coarsely crushed pieces into defibratedmaterial, a web forming unit configured to form a web by accumulatingdefibrated material, and a shaping unit configured to form a sheet fromthe web. The crusher unit is positioned vertically below the shapingunit.

In this sheet manufacturing apparatus, since the crusher unit isdisposed in a space below the shaping unit, waste space can be made assmall as possible and therefore the installation area of the sheetmanufacturing apparatus can be minimized.

In the sheet manufacturing apparatus described above, the shaping unitmay include a cutter unit configured to cut off a side end portion ofthe sheet which extends in a transport direction in which the sheet istransported, and at least a portion of the crusher unit may bepositioned vertically below the cutter unit.

In this sheet manufacturing apparatus, the remnants produced in thecutter unit can be introduced into the crusher unit by gravity forreuse.

In the forgoing sheet manufacturing apparatus according to theinvention, the shaping unit may include a pressurization unit configuredto pressurize the web, a heater unit configured to heat the webpressurized by the pressurization unit, and a cutter unit configured tocut the sheet obtained by heating the web by the heater unit, and thecrusher unit may be positioned vertically below the heater unit and thecutter unit.

In this sheet manufacturing apparatus, maintenance of the pressurizationunit can be easily performed even though the crusher unit is disposedvertically below the shaping unit.

This sheet manufacturing apparatus may further include a receiver unitprovided vertically below the pressurization unit, the heater unit, andthe cutter unit and the receiver unit may guide paper powder produced inthe shaping unit to a defibrator unit side.

In this sheet manufacturing apparatus, the paper powder produced in theshaping unit can also be reused.

The foregoing sheet manufacturing apparatus may further include asupplying unit configured to hold the raw material and to supply the rawmaterial to the crusher unit and a discharge unit configured to hold thesheet formed by the shaping unit. Furthermore, the supplying unit may bepositioned at a first side wall of a casing of the sheet manufacturingapparatus and the discharge unit may be positioned at a second side wallcontinuous to the first side wall of the casing of the sheetmanufacturing apparatus.

This sheet manufacturing apparatus is convenient for users.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a schematic diagram of a sheet manufacturing apparatusaccording to an exemplary embodiment of the invention.

FIG. 2 is a schematic plan view of the sheet manufacturing apparatusaccording to the exemplary embodiment.

FIG. 3 is a schematic rear view of the sheet manufacturing apparatusaccording to the exemplary embodiment.

FIG. 4 is a schematic front view of the sheet manufacturing apparatusaccording to the exemplary embodiment.

FIG. 5 is a schematic right side view of the sheet manufacturingapparatus according to the exemplary embodiment.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Preferred exemplary embodiments of the invention will be described indetail hereinafter with reference to the drawings. It is to be notedthat the exemplary embodiments described below are not meant to undulylimit the contents of the invention described in the appended claims.Also note that it is not necessarily the case that all theconfigurations and the like described below are indispensableconstituent features of the invention.

A sheet manufacturing apparatus according to an exemplary embodimentincludes a crusher unit that coarsely crushes raw material that containsfiber into coarsely crushed pieces, a defibrator unit that defibratescoarsely crushed pieces into defibrated material, a web forming unitthat forms a web by accumulating defibrated material, and a shaping unitthat forms a sheet from the web. The coarse crusher unit is disposedvertically below the shaping unit.

1. Sheet Manufacturing Apparatus 1.1. Configuration

First, a sheet manufacturing apparatus according to an exemplaryembodiment of the invention will be described with reference todrawings. FIG. 1 is a schematic diagram of a sheet manufacturingapparatus 100 according to the exemplary embodiment.

The sheet manufacturing apparatus 100, as shown in FIG. 1, includes asupplying unit 10, a manufacturing unit 102, and a control unit 140. Themanufacturing unit 102 manufactures a sheet. The manufacturing unit 102includes a coarse crusher unit 12, a defibrator unit 20, a classifierunit 30, a screening unit 40, a first web forming unit 45, a mixer unit50, an accumulation unit 60, a second web forming unit 70, a sheetforming unit 80, and a cutter unit 90.

The supplying unit 10 supplies a raw material to the coarse crusher unit12. The supplying unit 10 is, for example, an automatic feeding unit forcontinuously feeding the raw material into the coarse crusher unit 12.The raw material supplied by the supplying unit 10 is, for example, amaterial that contains fiber of waste paper, pulp sheets, etc.

The coarse crusher unit 12 cuts the raw material supplied by thesupplying unit 10 into small pieces in the air. As for the shape andsize of the small pieces, the pieces are, for example, severalcentimeters by several centimeters. In the example shown in FIG. 1, thecoarse crusher unit 12 includes a coarse crusher blade 14. By the coarsecrusher blade 14, the raw material fed into the coarse crusher unit 12can be cut. The coarse crusher unit 12 is, for example, a shredder. Theraw material cut by the coarse crusher unit 12 is received by a hopper 1and then transferred (transported) to the defibrator unit 20 through apipe 2.

The defibrator unit 20 defibrates the raw material cut by the coarsecrusher unit 12. Note that the “defibrate” means to disentangle a rawmaterial (defibration object) in which a plurality of fibers are boundinto separate individual fibers. The defibrator unit 20 also has afunction of separating substances, such as resin particles, ink, toner,or a blur-preventing agent adhering to the raw material, from thefibers.

The material that has passed through the defibrator unit 20 is referredto as “defibrated material”. In some cases, the “defibrated material”contains not only defibrated material fibers that have been disentangledbut also resin particles (particles of a resin for binding fibers)separated from the fibers at the time of disentangling the fibers,coloring agents such as ink or toner, additives such as ablur-preventing material or a paper strength additive. The shape ofdisentangled pieces of the defibrated material is a string shape or aribbon shape. The disentangled defibrated material may be in a state inwhich the material is not intertwined with the other disentangled fibers(independent state) and may also be in a state in which the disentangleddefibrated material is tangled with other disentangled fibers (a statein which so-called “lumps” have been formed).

The defibrator unit 20 performs defibration in a dry process in theatmosphere (air). Concretely, the defibrator unit 20 used is an impellermill. The defibrator unit 20 has a function of sucking the raw materialto produce an air stream that discharges the defibrated material.Therefore, due to the air stream that the defibrator unit 20 produces,the defibrator unit 20 can suck the raw material from the introductionport 22 together with the air stream, perform the defibration process,and transport the defibrated material to the discharge port 24. Thedefibrated material that has passed through the defibrator unit 20 istransferred to the classifier unit 30 through a pipe 3.

The classifier unit 30 classifies the defibrated material that haspassed through the defibrator unit 20. Concretely, the classifier unit30 separates and removes from the defibrated material substances thatare relatively small in size or low in density (resin particles,coloring agents, additives, etc.) This process increases the proportionof fibers that are relatively large in size or high in density in thedefibrated material.

As the classifier unit 30, an air stream-type classifier is used. Theair stream-type classifier produces a swirling air stream to separatesubstances to be classified according to different centrifugal forces onthe substances based on their sizes and densities. By adjusting thespeed of the air stream and the centrifugal force, the classificationpoint can be adjusted. Concretely, as the classifier unit 30, a cyclone,an elbow jet, an eddy classifier, etc. may be used. In particular, acyclone as shown in drawings is simple in structure and can be suitablyused as the classifier unit 30.

The classifier unit 30 includes, for example, an introduction port 31, acylindrical portion 32 to which the introduction port 31 is connected,an inverted cone-shaped portion 33 provided under and extendingcontinuously from the cylindrical portion 32, a lower discharge port 34provided in a center portion of a lower portion of the invertedcone-shaped portion 33, and an upper discharge port 35 provided in acenter portion of an upper portion of the cylindrical portion 32.

In the classifier unit 30, the air stream introduced through theintroduction port 31 and carrying defibrated material changes intocircumferential motion in the cylindrical portion 32. Due to this, theintroduced defibrated material is subjected to centrifugal force, sothat the classifier unit 30 is able to separate the defibrated materialinto fibers that are larger in size and higher in density than resinparticles and ink particles (first classified material) and resinparticles, coloring agents, additives, etc. that are smaller in size andlower in density than the fibers (second classified material). The firstclassified material is discharged from the lower discharge port 34 intoa pipe 4 and then introduced into the screening unit 40. On the otherhand, the second classified material is discharged from the upperdischarge port 35 into a dust collector unit 36 via a pipe 5.

The screening unit 40 introduces through an introduction port 42 thefirst classified material (the defibrated material having beendefibrated by the defibrator unit 20) that has passed through theclassifier unit 30, and then screens the first classified materialaccording to the lengths of the fibers. The screening unit 40 is, forexample, a sieve. The screening unit 40 has a mesh (a filter, a screen)and is able to separate the first classified material into fibers orparticles that are smaller than the size of the aperture of the mesh(materials that pass through the mesh, referred to as “first screenedmaterial”) and fibers, undefibrated pieces, and lumps which are largerthan the size of the aperture of the mesh (substances that do not passthrough the mesh, referred to as “second screened material”). Forexample, the first screened material is received by a hopper 6 and thenis transferred to the mixer unit 50 through a pipe 7. The secondscreened material is returned from the discharge port 44 to thedefibrator unit 20 through a pipe 8. Concretely, the screening unit 40is a cylindrical sieve capable of being rotated by a motor. The mesh ofthe screening unit 40 is, for example, a metal mesh, an expanded metalformed by stretching a slitted metal sheet, or a punched metal formed byperforating a metal sheet with a press machine or the like.

The first web forming unit 45 transports the first screened materialthat has passed through the screening unit 40 to the mixer unit 50. Thefirst web forming unit 45 includes a mesh belt 46, tension rollers 47,and a suction unit (suction mechanism) 48.

The suction unit 48 is able to draw onto the mesh belt 46 the firstscreened material having passed through an opening (a mesh opening) ofthe screening unit 40 and dispersed in air. The first screened materialaccumulates on the mesh belt 46 in motion to form a web V. The basicconfigurations of the mesh belt 46, the tension rollers 47, and thesuction unit 48 are substantially the same as those of a mesh belt 72,tension rollers 74, and a suction mechanism 76 of the second web formingunit 70 (described later).

The web V, because of having passed through the screening unit 40 andthe first web forming unit 45, forms so as to contain a large amount ofair and therefore be soft and swollen. The web V accumulated on the meshbelt 46 is fed into the pipe 7 and then transported to the mixer unit50.

The mixer unit 50 mixes the first screened material having passedthrough the screening unit 40 (the first screened material having beentransported by the first web forming unit 45) and an additive thatcontains a resin. The mixer unit 50 includes an additive supplying unit52 that supplies the additive, a pipe 54 for transporting the additiveand the first screened material, and a blower 56. In the example shownin FIG. 1, the additive is supplied from the additive supplying unit 52into the pipe 54 via a hopper 9. The pipe 54 is continuous to the pipe7.

The mixer unit 50 produces an air stream by using the blower 56 so thatthe first screened material and the additive can be mixed in the pipe 54and transported through the pipe 54. Incidentally, the mechanism thatmixes the first screened material and the additive is not particularlylimited but may be, for example, a mechanism that stirs the firstscreened material and the additive by using blades that turn at highspeed or a mechanism such as a V-shape mixer that utilizes rotation of acontainer.

The additive supplying unit 52 may be, for example, a screw feeder asshown in FIG. 1, a disc feeder (not shown), etc. The additive suppliedfrom the additive supplying unit 52 includes a resin for binding aplurality of fibers. At the time point when the resin is supplied, theplurality of fibers are not bound yet. The resin melts and binds thefibers when passing through the sheet forming unit 80.

The resin supplied from the additive supplying unit 52 is athermoplastic resin or a thermosetting resin. Examples of the resininclude AS resin, ABS resin, polypropylene, polyethylene, polyvinylchloride, polystyrene, acrylic resin, polyester resin, polyethyleneterephthalate, polyphenylene ether, polybutylene terephthalate, nylon,polyamide, polycarbonate, polyacetal, polyphenylene sulfide, polyetherether ketone, etc. These resins may be used singly or in an appropriatemixture. The additive supplied from the additive supplying unit 52 maybe in a fibrous state or a powder state.

Incidentally, the additive supplied from the additive supplying unit 52may contain, besides the resin for binding fibers, a colorant forcoloring the fibers, an aggregation preventing material for preventingaggregation of fibers, or a flame retardant for making the fibers andthe like less easy to burn according to the kind of the sheet to bemanufactured. The mixture having passed through the mixer unit 50 (themixture of the first screened material and the additive) is transferredto the accumulation unit 60 through the pipe 54.

The accumulation unit 60 introduces the mixture having passed throughthe mixer unit 50 from the introduction port 62, unravels theintertwined defibrated material (fibers), and then causes the unraveledfibers to fall while dispersing in air. Furthermore, if the resin in theadditive supplied from the additive supplying unit 52 is fibrous, theaccumulation unit 60 unravels the intertwined resin. Due to this, theaccumulation unit 60 is able to cause the mixture to accumulate in thesecond web forming unit 70 with high uniformity.

The accumulation unit 60 in this example is a cylindrical sieve thatrotates. The accumulation unit 60 includes a mesh and allows fibers orparticles that are contained in the mixture having passed through themixer unit 50 and that are smaller than the aperture size of the mesh(the fibers or particles that pass through the mesh) to fall. Theconfiguration of the accumulation unit 60 is, for example, the same asthe configuration of the screening unit 40.

Note that the “sieve” of the accumulation unit 60 does not need to havea function of screening a specific object. Specifically, the “sieve”used as the accumulation unit 60 means an element that includes a mesh,and the accumulation unit 60 may allow all the mixture introduced intothe accumulation unit 60 to fall.

The second web forming unit 70 accumulates the material having passedthrough the accumulation unit 60 so as to form the web W. The second webforming unit 70 includes, for example, the mesh belt 72, the tensionrollers 74, and the suction mechanism 76.

The mesh belt 72, while moving, accumulates the material that has passedthrough the opening (aperture of the mesh) of the accumulation unit 60.The mesh belt 72 is supported with tension by the tension rollers 74 andis configured so as not to easily allow the material having come throughthe opening to pass through but so as to allow air to pass through. Themesh belt 72 moves as the tension rollers 74 rotate about their ownaxes. While the mesh belt 72 continuously moves, the material havingpassed through the accumulation unit 60 continuously falls andaccumulates on the mesh belt 72 to form the web W on the mesh belt 72.The mesh belt 72 is made of, for example, a metal, a resin, a cloth, anon-woven fabric, etc.

The suction mechanism 76 is provided below the mesh belt 72 (provided atthe opposite side to the accumulation unit 60). The suction mechanism 76is capable of producing a downward air stream (air stream toward themesh belt 72 from the accumulation unit 60). Due to the suctionmechanism 76, the mixture dispersed in air by the accumulation unit 60can be drawn onto the mesh belt 72. Therefore, the speed of dischargefrom the accumulation unit 60 can be made high. Furthermore, due to thesuction mechanism 76, a fall path of the mixture can be provided withdownward air flow, so that the defibrated material and the additive canbe prevented from intertwining during fall.

Due to the accumulation unit 60 and the second web forming unit 70 (aweb forming step) as described above, a web W that contains a largeamount of air and that is soft and swollen is formed. The web Waccumulated on the mesh belt 72 is transported to the sheet forming unit80.

In the example shown in FIG. 1, a moisture-adjusting unit 78 thatadjusts the moisture in the web W is provided. The moisture-adjustingunit 78 is capable of adjusting the ratio between the amounts of the webW and water in the web W by adding water or steam to the web W.

The sheet forming unit 80 shapes (forms) the web W accumulated on themesh belt 72 into a sheet S by pressurizing and heating the web W. Inthe sheet forming unit 80, because the mixture of the defibratedmaterial and the additive mixed in the web W is heated, a plurality offibers in the mixture can be bound by the additive (resin).

The sheet forming unit 80 is, for example, a heating roller (heaterroller), a hot press molding machine, a hot plate, a warm air blower, aninfrared heater, or a flash fixer unit. In the example shown, the sheetforming unit 80 includes a first binder unit 82 and a second binder unit84, and each binder unit 82, 84 includes a pair of heating rollers 86.Because the binder units 82 and 84 are provided as the heating rollers86 in this example, the web W can be continuously transported whilebeing shaped into the sheet S, in contrast with a configuration in whichthe binder units 82 and 84 are provided as platy press apparatuses (flatpress apparatuses). Incidentally, the number of heating rollers 86 isnot particularly limited.

The cutter unit 90 cuts the sheet S formed by the sheet forming unit 80.In the example shown in FIG. 1, the cutter unit 90 includes a firstcutter unit 92 that cuts the sheet S along a direction that intersectsthe transport direction of the sheet S and a second cutter unit 94 thatcuts the sheet S along a direction substantially parallel to thetransport direction. The second cutter unit 94, for example, cuts thesheet S that has passed through the first cutter unit 92.

In the foregoing manner, a cut-sheet type sheet S having a predeterminedsize is formed. The thus obtained cut sheet S is discharged to adischarge unit 96.

1.2. Arrangement

With reference to FIG. 2, arrangement of various process units in thesheet manufacturing apparatus 100 will be described. FIGS. 2 to 5schematically show the sheet manufacturing apparatus 100 according tothe exemplary embodiment. FIG. 2 is a plan view, FIG. 3 is a rear view,FIG. 4 is a front view, and FIG. 5 is a right side view of the sheetmanufacturing apparatus 100. In FIGS. 2 to 4, for illustration ofinternal structures, a side wall at a near side in each drawing isomitted, and an arrangement of process units at the far side in eachdrawing is also omitted. Incidentally, the process units of the sheetmanufacturing apparatus 100 shown in FIGS. 2 to 5 have already beendescribed above in “1.1. Configuration” and redundant descriptions willbe avoided below.

In FIG. 2, the side at which an operation unit 141 (a control unit 140)by which a user operates the sheet manufacturing apparatus 100 isdisposed is a front side of the sheet manufacturing apparatus 100. Whenthe side at which the operation unit 141 is positioned is the frontside, the defibrator unit 20 is positioned at the rear side and theshaping unit 106 is positioned at the front side.

As shown in FIG. 2, the sheet manufacturing apparatus 100 has a casing150 that does not contain either the supplying unit 10 or the dischargeunit 96 and that has a substantially quadrangular shape in a plan viewwhose four sides are first to fourth side walls 150 a to 150 d. Thefirst to fourth side walls 150 a to 150 d extend upward from a machinebase 150 e. The first side wall 150 a provided on the front side is afront surface of the sheet manufacturing apparatus 100 and faces thethird side wall 150 c provided on the rear side. The second side wall150 b and the fourth side wall 150 d are disposed so as to connect twoopposite end portions of the first side wall 150 a and two opposite endportions of the third side wall 150 c.

The supplying unit 10 and the discharge unit 96 are provided outside thecasing 150 and adjacent to the first side wall 150 a and the second sidewall 150 b, respectively. In this exemplary embodiment, the casing 150is rectangular in a plan view, with the first and third side walls 150 aand 150 c being longer than the second and fourth side walls 150 b and150 d. The first to fourth side walls 150 a to 150 d are rectangularplaty bodies having the same height and, therefore, the casing 150 hassubstantially the shape of a rectangular parallelepiped.

The supplying unit 10 holds a raw material and supplies the raw materialto the coarse crusher unit 12. The supplying unit 10 is positioned atthe first side wall 150 a of the casing 150 of the sheet manufacturingapparatus 100. The supplying unit 10 is disposed adjacent to an externalsurface of the first side wall 150 a and toward (near) the second sidewall 150 b. The discharge unit 96 holds cut sheets S1 formed by theshaping unit 106. The discharge unit 96 is positioned at the second sidewall 150 b continuous to the first side wall 150 a of the casing 150 ofthe sheet manufacturing apparatus 100. The discharge unit 96 is disposedadjacent to an external surface of the second side wall 150 b and towardthe first side wall 150 a. This arrangement of the supplying unit 10 andthe discharge unit 96 on the continuous side walls is convenient for theuser.

The sheet manufacturing apparatus 100 includes at least the coarsecrusher unit 12 that coarsely crushes the raw material containing fibersinto coarsely crushed pieces, the defibrator unit 20 that defibrates thecoarsely crushed pieces provided by the coarse crusher unit 12 into adefibrated material, the second web forming unit 70 that accumulates thedefibrated material provided by the defibrator unit 20 so as to form theweb W, and the shaping unit 106 that shapes the web W provided by thesecond web forming unit 70 into cut sheets S1.

Furthermore, the shaping unit 106 includes the sheet forming unit 80that includes a pressurization unit 81 that pressurizes the web W and aheater unit 83 that heats the web W pressurized by the pressurizationunit 81. The shaping unit 106 further includes the cutter unit 90 thatcuts the continuous sheet S heated by the heater unit 83.

The sheet manufacturing apparatus 100 has in front and rear portionsthereof two transport lines A and B that transport the raw material orthe sheet S. As for the front-side transport line B, the set of theaccumulation unit 60 and the second web forming unit 70, the sheetforming unit 80 (the pressurization unit 81 and the heater unit 83), andthe cutter unit 90 are disposed in order along the first side wall 150 aside from the fourth side wall 150 d toward the second side wall 150 b.A downstream-side end portion of the front-side transport line B isconnected toward the discharge unit 96.

As for the rear-side transport line A, the defibrator unit 20, theclassifier unit 30, the screening unit 40, and the mixer unit 50 aredisposed in order along the third side wall 150 c side from the secondside wall 150 b to the fourth side wall 150 d. This two-row arrangementof the front and rear-side transport lines allows a shorter length ofthe entire apparatus than a single-row transport line arrangement.Therefore, the sheet manufacturing apparatus 100 can be provided in sucha size as to be placed in a limited space such as an office or awarehouse.

As shown in FIGS. 2, 4 and 5, the coarse crusher unit 12 is positionedvertically below the shaping unit 106. Because the coarse crusher unit12 is disposed in a space below the shaping unit 106, waste space can bemade as small as possible and therefore the installation area of thesheet manufacturing apparatus 100 can be minimized. The raw materialsupplied from the supplying unit 10 is supplied to the defibrator unit20 of the rear-side transport line A via the coarse crusher unit 12disposed vertically below the shaping unit 106.

The order of the processes performed by the process units is asdescribed in “1.1. Configuration”, and is indicated in FIG. 2 bysolid-line arrows that connect the process units (pipes and the like areomitted from the illustration). The process units will be described inthe order indicated by the arrows. When the raw material is suppliedfrom the supplying unit 10 into the casing 150, the raw material iscrushed into coarsely crushed pieces by the coarse crusher unit 12provided vertically below the shaping unit 106 and then is sent to therear-side transport line A. The coarsely crushed pieces are transportedinto the defibrator unit 20 disposed at the second side wall 150 b sideand are defibrated by the defibrator unit 20 into a defibrated material.The defibrated material is classified into the first and secondclassified materials by the classifier unit 30 disposed near the centerof the casing 150. The first classified material is screened into thefirst screened material by the screening unit 40. The first screenedmaterial is mixed with the additive that contains a resin by the mixerunit 50. The obtained mixture is sent to the front-side transport lineB. Then, in the front-side transport line B, the mixture is transportedto and unraveled by the accumulation unit 60 provided at the fourth sidewall 150 d side, and is accumulated to form the web W in the second webforming unit 70 provided vertically below the accumulation unit 60. Theweb W is transported to the sheet forming unit 80, in which the web W isshaped into a continuous sheet S. The continuous sheet S is transportedto the cutter unit 90 provided at the second side wall 150 b and is cutthereby into cut sheets S1. The cut sheets S1 are discharged through thedischarge opening 154 into the discharge unit 96 provided outside thecasing 150.

Although the exemplary embodiment has been described in conjunction withthe example in which the two-row transport line is employed, thetransport line may be provided as a transport line of three or more rowsor may also be a single-row transport line that extends in thefront/rear direction.

1.3. Cutter Unit

With reference to FIGS. 4 and 5, the cutter unit 90 will be described indetail.

The shaping unit 106 includes the cutter unit 90 provided at a locationthat is within the casing 150 and that is at the second side wall 150 bside. The cutter unit 90 includes a first cutter unit 92 and a secondcutter unit 94.

The first cutter unit 92 cuts the continuous sheet S transported fromthe sheet forming unit 80 in a cutting direction orthogonal to thetransport direction M of the continuous sheet S. The first cutter unit92 includes a blade portion whose lower end is formed as a cutting edgethat cuts the continuous sheet S and a cutting/driving unit that raisesand lowers the blade portion relative to the continuous sheet S.According to a command from the control unit 140, the cutting/drivingunit lowers the blade portion to the continuous sheet S at predeterminedintervals to cut off a predetermined cut sheet S1 length and raises theblade portion after the cutting. The length of the cut sheet S1 at thisstage is equal to the length of the cut sheet S1 as a final product.

In this specification, the “width of the sheet” means the length of thesheet S, S1 in the direction orthogonal to the transport direction M andthe “length of the sheet” is the length of the sheet S, S1 in adirection parallel to the transport direction M.

The cutting edge of the blade portion extends over the entire width ofthe continuous sheet S in the direction orthogonal to the transportdirection M. The first cutter unit 92 is of a so-called guillotinecutter system in this example but may employ various known cuttingmechanisms for papers, such as a rotary cutter system that uses adisc-shaped blade that rotates.

The second cutter unit 94 is positioned at the downstream side of thefirst cutter unit 92 in the transport direction M. The second cutterunit 94 further cuts the cut sheet S1 having been cut by the firstcutter unit 92, in a direction along the transport direction M.Specifically, the second cutter unit 94 cuts opposite side end portionsof the cut sheet S1 which extend in the transport direction. In the casewhere the first cutter unit 92 is not provided (where the product is nota cut sheet but a continuous sheet that is wound into a roll), oppositeside end portions of a continuous sheet S which extend in the transportdirection may be cut. The second cutter unit 94, sometimes calledslitter, cuts two opposite end portions of the cut sheet S1 in the widthdirection so that the obtained width equals a predetermined width of thecut sheet S1 as a final product.

As shown in FIG. 5, the second cutter unit 94 cuts the two opposite endportions of the cut sheet S1 in the width direction by using cuttingblades that are disposed at two locations near the two opposite endportions of the cut sheet S1 in the width direction. The second cutterunit 94 includes a first side end cutter unit 94 a and a second side endcutter unit 94 b.

Cutting blades of the first side end cutter unit 94 a and the secondside end cutter unit 94 b are disc-shaped rotary blades as shown in FIG.4. More specifically, two cutting blades are fixed on the same rotationshaft and rotated to cut the cut sheet S1 so as to always provide aconstant width of the cut sheet S1 as shown in FIG. 5. The first sideend cutter unit 94 a and the second side end cutter unit 94 bcontinuously cuts the cut sheet S1 that is being transported in thetransport direction M. Note that although the cutting blades of thesecond cutter unit 94 in this example are rotary blades, this is notrestrictive but any suitable known cutters for use in slitters may beused.

The side end portions of the cut sheet S1 which extend in the transportdirection are portions that become no longer needed in the processing ofthe continuous sheet S into the final-product cut sheet S1 and,specifically, portions from the two opposite ends of the continuoussheet S in the width direction to the first side end cutter unit 94 aand to the second side end cutter unit 94 b. The side end portions arecut off in order to trim the shape of the two opposite ends of the cutsheet S1 and also because the grammage of the side end portions of thecut sheets S1 tends to be less than the grammage needed for the finalproducts. However, since the side end portions do not have any problemsabout the fibers of the defibrated material themselves, remnants S2(FIG. 5) cut off from the sheet S1 can be sufficiently reused as a rawmaterial of the continuous sheet S by returning the remnant S2 to thedefibrator unit 20 for the series of processes.

In order to efficiently reuse the remnants S2, at least a portion of thecoarse crusher unit 12 is positioned vertically below the cutter unit90. Due to the provision of the coarse crusher unit 12 vertically belowthe cutter unit 90, the remnants S2 produced in the cutter unit 90 canbe introduced into the coarse crusher unit 12 by gravity. Moreconcretely, the coarse crusher unit 12 has a guide 13 that is providedvertically below the second cutter unit 94. The guide 13 is formed by aframe made up of platy parts and expands toward its tip. The guide 13guides the falling remnants S2 to the coarse crusher blade 14 so thatthe remnants S2 slide down. The guide 13 has in a side facing a supplyopening 152 of the supplying unit 10 an opening for receiving the rawmaterial supplied from the supplying unit 10 to the coarse crusher unit12.

The coarse crusher unit 12 is positioned vertically below the heaterunit 83 and the cutter unit 90. This disposal of the coarse crusher unit12 facilitates performing maintenance of the pressurization unit 81 eventhough the coarse crusher unit 12 is disposed vertically below theshaping unit 106. Because the pressurization unit 81 has apressurization mechanism that is larger and heavier than the heater unit83 and the cutter unit 90, the disposal of the pressurization mechanismat a lower side of the web W makes it easy to pull out thepressurization mechanism, for example, to the outside of the casing 150,and thus facilitates performing maintenance.

The coarsely crushed pieces of the remnants S2 coarsely crushed by thecoarse crusher unit 12 freely fall downward from the coarse crusher unit12, together with coarsely crushed pieces of the raw material suppliedfrom the supplying unit 10, so that the coarse crushed pieces arereceived by the hopper 1 and gathered into the pipe 2 and aretransported to the defibrator unit 20 through the pipe 2 due to airstreams. Because the remnants S2, due to their low grammage, are notsufficiently pressurized by the pressurization unit 81, the remnants S2can be defibrated by the defibrator unit 20 even if they are notcoarsely crushed. However, if the remnants S2 are coarsely crushedsimilarly to the raw material, the remnants S2 can be more certainlydefibrated by the defibrator unit 20. Furthermore, if the remnants S2are made coarsely crushed pieces, the remnants S2 can be easilytransported by an air stream produced by the defibrator unit 20.

The coarse crusher unit 12 is a unit for breaking the raw materialsupplied from the supplying unit 10 into small pieces. If the coarsecrusher unit 12 is used also to break the remnants S2 into small pieces,it is not necessary to separately provide a shredder for remnants S2 andtherefore it is possible to achieve low cost, space saving, and energysaving.

1.4. Receiver Unit

A receiver unit is provided vertically below the pressurization unit 81,the heater unit 83, and the cutter unit 90. In the example shown inFIGS. 4 and 5, the receiver unit has been formed by stretching(extending) a hopper 1. The hopper 1 (the receiver unit) guides paperpowder produced in the shaping unit 106 to the defibrator unit 20 side.

As for the web W accumulated in the second web forming unit 70, the twoopposite side end portions are accompanied by a defibrated material thatis so low in grammage as to be incapable of maintaining a shape as theweb W despite being pressurized by the pressurization unit 81 andtherefore become paper powder. According to the related art, a part ofthis paper powder is transported together with the web W and anotherpart separates from the web W to remain in an intermediate portion ofthe transport path and becomes lumps of paper powder. Then, if suchlumps of paper powder are left remaining, lumps can mix into the web Wsome time, impeding the transport of the continuous sheet S or producinga speckled pattern in the cut sheet S1 as a final product.

As shown in FIGS. 4 and 5, in the pressurization unit 81, the heaterunit 83, and the cutter unit 90, a platy guide 87 that at least hassubstantially the same width as the product cut sheet S1 is providedunder the web W and the continuous sheet S. The web W or the continuoussheet S is transported by a plurality of rollers such as pressurerollers 85 and heating rollers 86. At that time, paper powder adjacentto portions of the web W or the continuous sheet S which are wider thanthe platy guide 87, more specifically, adjacent to the two opposite endsof the wider portions, falls outside the guide 87.

The hopper 1 (the receiver unit) has a greater width than the platyguide 87 and therefore is capable of receiving the falling paper powder.The hopper 1 (the receiver unit) extends in the downstream side of thesecond web forming unit 70 in which paper powder occurs, that is,extends vertically below the pressurization unit 81, the heater unit 83,and the cutter unit 90. The hopper 1 (the receiver unit) is inclineddownward toward the pipe 2 and serves as a chute down which the paperpowder slides. The paper powder is then transported through the pipe 2to the defibrator unit 20.

Because the hopper 1 (the receiver unit) as described above is provided,the paper powder produced in the shaping unit 106 can also be reused.Furthermore, because the paper powder is guided to the hopper 1 (thereceiver unit), transport impediment or a speckled pattern in the cutsheet S1 can be prevented.

Note that since the paper powder can be easily defibrated, the directtransport of the paper powder from the hopper 1 (the receiver unit) tothe defibrator unit 20 in the exemplary embodiment is not restrictivebut a receiver unit may be provided so as to guide the paper powder tothe coarse crusher unit 12. In that case, the paper powder is guided bythe receiver unit to the coarse crusher unit 12, coarsely crushed by thecoarse crusher unit 12 to fall into the hopper 1, and then transportedto the defibrator unit 20.

The paper in this specification includes various kinds of paper such asa paper formed into a thin sheet shape from a raw material such as pulpor waste paper. Examples of the paper in this specification includerecording sheets for use for writing and printing, wall paper, wrappingpaper, colored paper, drawing paper, Kent paper, etc. The non-wovenfabric in this specification includes a non-woven fabric thicker andlower in strength than paper and, specifically, a general non-wovenfabric, fiber board, tissue paper (cleaning tissue paper), paper towel,a cleaner, a filter, a liquid (waste ink or oil) absorbent, a soundabsorbing material, a heat insulator, a cushioning material, a mat, etc.Incidentally, the raw material may be vegetable fiber such as cellulose,chemical fiber such as fibers of PET (polyethylene terephthalate),polyester, etc., animal fiber such as wool or silk.

According to the invention, the features and effects mentioned in thesubject application may be partly omitted and the embodiments andmodifications may be combined in various manners.

The present invention includes configurations that are substantially thesame as the configuration described above in conjunction with theexemplary embodiments (configurations that are the same in function,method, and result or the same in purpose and effect as the foregoingconfiguration). Furthermore, the invention encompasses configurationsobtained by replacing unessential portions of the configurationsdescribed in conjunction with the exemplary embodiments with differentportions. Further, the invention encompasses configurations that achievethe same operation and effects or accomplish the same purposes as theconfigurations described above in conjunction with the exemplaryembodiments. Still further, the invention encompasses configurationsobtained by adding known technologies to the configurations describedabove in conjunction with the exemplary embodiments.

The entire disclosure of Japanese Patent Application No. 2015-044374,filed Mar. 6, 2015 is expressly incorporated by reference herein.

What is claimed is:
 1. A sheet manufacturing apparatus comprising: acrusher unit configured to coarsely crush raw material that containsfiber into coarsely crushed pieces; a defibrator unit configured todefibrate coarsely crushed pieces into defibrated material; a webforming unit configured to form a web by accumulating defibratedmaterial; and a shaping unit configured to form a sheet from the web,wherein the crusher unit is positioned vertically below the shapingunit.
 2. The sheet manufacturing apparatus according to claim 1,wherein: the shaping unit includes a cutter unit configured to cut off aside end portion of the sheet which extends in a transport direction inwhich the sheet is transported; and at least a portion of the crusherunit is positioned vertically below the cutter unit.
 3. The sheetmanufacturing apparatus according to claim 1, wherein the shaping unitincludes: a pressurization unit configured to pressurize the web; aheater unit configured to heat the web pressurized by the pressurizationunit; and a cutter unit configured to cut the sheet obtained by heatingthe web by the heater unit, and wherein the crusher unit is positionedvertically below the heater unit and the cutter unit.
 4. The sheetmanufacturing apparatus according to claim 3, further comprising areceiver unit provided vertically below the pressurization unit, theheater unit, and the cutter unit, wherein the receiver unit configuredto guide paper powder produced in the shaping unit to a defibrator unitside.
 5. The sheet manufacturing apparatus according to claim 1, furthercomprising: a supplying unit configured to hold the raw material andsupply the raw material to the crusher unit; and a discharge unitconfigured to hold the sheet formed by the shaping unit, and wherein thesupplying unit is positioned at a first side wall of a casing of thesheet manufacturing apparatus, and wherein the discharge unit ispositioned at a second side wall continuous to the first side wall ofthe casing of the sheet manufacturing apparatus.